The overall purpose is to understand the chemical architecture of myelin and the relationships between its protein and lipid components. Primary emphasis is placed on the chemistry of the proteolipid protein of myelin. During the coming year we will continue to direct a major effort towards the long range goal of determining the amino acid sequence of proteolipid protein from bovine brain white matter (myelin proteolipid). We plan to a) complete the sequence of a chloroform-methanol soluble tryptic peptide of molecular weight of approximately 4000, b) study the fragments obtained by chemical cleavage of the protein and c) investigate the monomeric form(s) of the protein which we have recently observed. Another aspect of the program involves a study of the immunological properties of the proteolipid apoprotein. Anti-apoprotein antibodies have been demonstrated by double immunodiffusion. We now plan to a) develop an enzyme linked immunospecific assay (ELISA) to quantitate the antibodies, b) use the assay to follow the antibody response in animals injected with apoprotein and c) study serum and CSF of patients with demyelinating diseases. These studies address fundamental problems related to myelin and should contribute to an understanding of the normal process of mylelination and abnormalities which occur in demyelinating diseases including multiple sclerosis and diseases of genetic and environmental origin.